Various prior art transmission systems have been described in which a multi channel information signal, such as a multi channel audio signal, is transmitted via a transmission medium. Generally, use is made of matrixing in order to obtain first and second composite audio signals that can be retrieved upon reception and reproduced as a stereo audio signal. Reference is made in this respect to EP 678,226 A1, which is document (8) in the list of related documents.
The present invention, however, is not restricted to a transmission of multi channel information signals in matrixed form.
Upon encoding, the various information signals of the multi channel information signal are data compressed and combined into one serial datastream and subsequently transmitted via the transmission medium. Upon reception of the transmitted data, the various data compressed information signals are retrieved and data expanded so as to obtain replicas of the original information signals.
Compression means for bit rate reducing a signal has been described in published European patent applications 457,390A1 (PHN 13.328) and 457,391A1 (PHN 13.329), the documents (7a) and (7b) respectively in the list of references. Further, reference is made to two ISO/IEC standard documents, the documents (9) and (10) in the list of related documents, referred to as MPEG-1 and MPEG-2 standard documents.
The documents cited above generally relate to data compression based on subband coding. The invention is however not restricted to data compression based on subband coding. Other data compression techniques, such as transform coding, are equally well applicable.
Those skilled in the art are directed to the following citations: J.A.E.S., Vol. 40, No. 5, May 1992, pp. 376-382; "Matrixing of bitrate reduced audio signals" by W. R. Th. ten Kate et al, in Proc. of the ICASSP, Mar. 23-26, 1992, San Francisco, Vol. 2, pp. II-205 to II-208; U.S. patent application Ser. No. 08/427,646 (PHQ 93-002); European Patent Application no. 402,973 (PHN 13.241); European patent application no. 497,413A1 (PHN 13.581); U.S. Pat. No. 4,620,311 (PHN 11.117); European Patent Application no. 400.755 (PHQ 89.018A); ISO/IEC international standard IS 11172-3, Information technology--coding of moving pictures and associated audio for digital storage media up to about 1.5 Mbit/s, Part 3: audio; and ISO/IEC international standard IS 13818-3, Information technology--coding of moving pictures and associated audio, Part 3: audio.
The above citations are hereby incorporated in whole by reference.